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fix: wrap-safe micros() timing so the stepper doesn't freeze every ~71 min #50

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fix: wrap-safe micros() timing so the stepper doesn't freeze every ~71 min #50

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4 changes: 2 additions & 2 deletions esphome/components/stepper/stepper.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@ namespace stepper {

static const char *const TAG = "stepper";

void Stepper::calculate_speed_(time_t now = micros()) {
void Stepper::calculate_speed_(uint32_t now = micros()) {
// delta t since last calculation in seconds
float dt = (now - this->last_calculation_) * 1e-6f;
this->last_calculation_ = now;
Expand All @@ -29,7 +29,7 @@ void Stepper::calculate_speed_(time_t now = micros()) {
}
this->current_speed_ = clamp(this->current_speed_, 0.0f, this->max_speed_);
}
Direction Stepper::should_step_(time_t now = micros()) {
Direction Stepper::should_step_(uint32_t now = micros()) {
this->calculate_speed_(now);
if (this->current_speed_ == 0.0f) {
this->current_direction = Direction::STANDSTILL;
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12 changes: 8 additions & 4 deletions esphome/components/stepper/stepper.h
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Original file line number Diff line number Diff line change
Expand Up @@ -43,16 +43,20 @@ class Stepper {
Direction current_direction{Direction::STANDSTILL};

protected:
void calculate_speed_(time_t now);
Direction should_step_(time_t now);
void calculate_speed_(uint32_t now);
Direction should_step_(uint32_t now);
int32_t should_step_();

float acceleration_{1e6f};
float deceleration_{1e6f};
float current_speed_{0.0f};
float max_speed_{1e6f};
time_t last_calculation_{0};
time_t last_step_{0};
// uint32_t (not time_t) so timing deltas of micros() are wrap-safe: micros()
// overflows every ~71.6 min, and unsigned subtraction wraps correctly whereas
// a signed/wider time_t delta goes negative across the wrap. Mirrors upstream
// esphome/components/stepper.
uint32_t last_calculation_{0};
uint32_t last_step_{0};
};

template<typename... Ts> class SetTargetAction : public Action<Ts...> {
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6 changes: 4 additions & 2 deletions esphome/components/tmc2209/stepper/tmc2209_stepper.cpp
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Expand Up @@ -48,7 +48,7 @@ void TMC2209Stepper::loop() {
TMC2209Component::loop();

// Compute speed and direction
const time_t now = micros();
const uint32_t now = micros();
this->calculate_speed_(now);
const int32_t to_target = (this->target_position - this->current_position);
this->current_direction = (to_target != 0 ? (Direction) (to_target / abs(to_target)) : Direction::STANDSTILL);
Expand All @@ -64,7 +64,9 @@ void TMC2209Stepper::loop() {
}

if (this->control_method_ == ControlMethod::PULSES_CONTROL) {
time_t dt = now - this->last_step_;
// uint32_t so the delta is wrap-safe across the ~71.6 min micros() overflow
// (a signed/wider time_t delta went negative on wrap, freezing STEP output).
uint32_t dt = now - this->last_step_;
if (dt >= (1 / (float) vactual_) * 1e6f) {
if (this->direction_ != this->current_direction) {
this->dir_pin_->digital_write(this->current_direction == Direction::BACKWARD);
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